1. Field of the Invention
The field of the invention is that of optical velocimeter probes used to define the velocity of particles in relative motion with respect to the probe.
2. Description of the Prior Art
At present, there are optical devices with two laser beams that interfere with each other so as to generate an ellipsoidal volume of measurement consisting of equidistant dark and luminous fringes. When a particle in motion goes through this volume of measurement, the signal collected by a photodetector includes indications on the velocity of this particle with respect to the optical probe. It is therefore possible, by analyzing the signal collected, to define the velocity of a particle considered.
This type of probe can be used to define the velocity of any particle that is small enough in relation to the interference fringes created and especially to define the speed of an aircraft, where the relative velocity of particles in the air in relation to said aircraft equipped with this type of velocimeter probe is known.
Indeed, with advances in terms of the miniaturization and cost of laser sources and especially laser diodes, it is becoming possible to make optical velocimeter probes of this kind, set up on board aircraft whose speed is to be measured.
The performance characteristics of this type of probe directly depend on the means of analysis of the signal collected by a photodetector for the extraction therefrom of the velocity parameter. This is why an object of the invention is an optical velocimeter probe of the type described here above, comprising highly efficient means of determining velocity.